This invention relates to a sheet feeding apparatus, particularly one which may be used in conjunction with an inserting device as, for example, the Phillipsburg Expediter inserter models.
In the above-mentioned inserters, gripper arms are provided adjacent separator assemblies to grip single, separated sheets and to deposit those sheets into an insert raceway for subsequent insertion into envelopes or the like. Timing of each gripper arm is controlled by cams in accordance with predetermined, sequential functions. Although standard sheet feeders have been found adequate for positioning single, non-folded sheets into position to be gripped by the gripper arms, where it is intended to feed accordion "Z" fold inserts problems resulting in jamming of the feeder or improper gripping by the gripper arm have been significant.
It is an object of this invention to provide a sheet feeding device capable of feeding accordion "Z" fold inserts which may easily be installed in standard inserter machines.
It is well known to use separator rollers adjacent abutment means to separate sheets stacked on end in a tray. One example of such a device is found in U.S. Pat. No. 2,762,623 to Uthenwoldt, et al. issued Sept. 11, 1956. In this patent, partially separated sheets are gripped between an idler roller and a feed roller driven separately from the separating roller. The separating roller is provided with an overrunning clutch so that a sheet may be drawn freely from the separator roller by the feed roller, which moves at a higher speed than the separator. The patented device also includes a booster roller which contacts the top sheet in the stack to urge a sheet into a ready position at the separator roller. If the feeding device of Uthenwoldt et al. were to be used with accordion "Z" fold inserts, the top sheet portion of the insert would tend to move ahead of the lower sheet portion which is held back by the abutment means, tending to warp the insert to some extent. When the thusly warped insert is then gripped by the higher speed feed roller, jamming is likely to result as the upper sheet portion, now somewhat ahead of the lower sheet portion, is gripped and pulled even further ahead of the lower sheet portion.
It is therefore an object of this invention to provide a sheet feeding device able to feed accordion fold inserts without jamming.
Because the sheet feeder of the present invention is to be used with a standard inserting machine, it is a further object of this invention to provide a completely self controlled unit which will respond to removal of a sheet by a gripper arm.